1. Field of the Invention
The present invention relates generally to a portable external defibrillator and, more particularly, to an accessory for a portable external defibrillator.
2. Related Art
Sudden cardiac arrest is a disruption of the heart""s functioning that causes a lack of blood flow to vital organs. In a majority of instances, sudden cardiac arrest is manifested as an abnormal or chaotic heart rhythm, called fibrillation. These instances are generally identifiable by the victim""s immediate loss of pulse, loss of consciousness and a cessation of breathing.
Sudden cardiac arrest has been attributed to over 350,000 deaths each year in the United States, making it one of the country""s leading medical emergencies. World-wide, sudden cardiac arrest has been attributed to a much larger number of deaths each year. Unless immediate medical intervention is initiated, sudden cardiac arrest can lead to death within a matter of minutes.
There are four critical components of medical treatment that must be administered to a victim of sudden cardiac arrest: (1) early access to emergency care; (2) early cardiopulmonary resuscitation to keep the blood oxygenated and flowing to the victim""s brain and other vital organs; (3) early defibrillation (the application of an electrical shock to the heart) to restore the heart""s regular rhythm; and (4) early access to advanced medical care. When a person is experiencing sudden cardiac arrest, the electrical activity within the heart becomes chaotic. An electric shock from a defibrillator can reorganize the electrical impulses to allow coordinated pumping action to resume. To administer this shock, special pads from a machine called a defibrillator are placed on the victim""s chest, and an electric shock is sent through the victim""s body from one pad to another. As used herein, the term xe2x80x9cpadsxe2x80x9d will include both pads and paddles.
If prompt cardiopulmonary resuscitation is followed by defibrillation within about four minutes, the victim""s chances of surviving sudden cardiac arrest can approach or exceed fifty percent. Prompt administration of defibrillation within the first critical minutes is considered one of the most important components of emergency medical treatment for preventing death from sudden cardiac arrest.
Since prompt defibrillation is critical to survival, portable defibrillators have been developed that can be carried to the victim""s location to defibrillate the victim prior to reaching a hospital. Also, there is a trend to place portable defibrillators in areas of hospitals not generally staffed with emergency personnel and in other public areas where difficult to reach patients are likely to be encountered, such as airplanes, airports, cruise liners, casinos, sports arenas and other populous facilities that are difficult or time consuming to access.
Automatic external defibrillators are typically used rather infrequently. Indeed, it has been estimated that a defibrillator will typically not be used more often than once every one to two years. To ensure that the defibrillator is operational, each conventional defibrillator periodically performs a test procedure to ensure the viability of its circuits. If any defect is detected, an alarm or other indication will be provided to the owner/operator of the defibrillator indicating that service is required. Optionally, the alarm may be communicated to a remote monitoring location over a network, by telephone, etc.
Various supplies are required to operate a defibrillator. Typically, automatic external defibrillators make use of either pre-connected or user attached self-adhesive pads. A gel conductor is provided in the center of each self-adhesive pad to provide a reliable contact between the victim""s skin and wires connected to the pads. The gel on the pads may dry over time, reducing the effectiveness of the pads and limiting the effective shelf-life of the pads to approximately two years.
Likewise, batteries provided to operate the defibrillator must be recharged or replaced when depleted. The shelf life of a battery, depending on the battery chemistry, is typically around five years.
Maintenance of a fleet of defibrillators is thus complicated by the numerous items necessary for operation of the defibrillator that must be monitored in addition to monitoring the operational status of the defibrillator itself. Accordingly, it would be advantageous to provide a system whereby the status of the defibrillator and items associated with operation of the defibrillator could be monitored easily.
The present invention relates to a defibrillation system that includes an automatic external defibrillator and a supply module containing items for use in connection with the automatic external defibrillator. The supply module may contain many items, including pads, ECG leads, gloves, CPR barrier masks, scissors, PCMCIA cards and batteries for the defibrillator, as well as any other components or supplies desired to be included by the operator or manufacturer. The supply module typically is physically coupled to the defibrillator to ensure the availability of the items during operation of the defibrillator. Items within the supply module such as the battery and pads or the supply module itself may be electrically coupled to the defibrillator to reduce the amount of time required to deploy the defibrillator when responding to an emergency medical situation. In another aspect of the invention, the supply module may be provided with a visible or electronically readable indicia of the shelf life of the supply module or one or more items contained by the supply module. A memory or other circuitry may be provided on the supply module to communicate with the defibrillator prior to, during or subsequent to operation of the defibrillator to facilitate exchanges of information between the supply module, defibrillator, defibrillator operator and defibrillator maintenance personnel.
In one embodiment, a defibrillation system includes an external defibrillator and a replaceable supply module, including pads and a battery, mounted on the external defibrillator. In this embodiment, the replaceable supply module may be physically or electrically connected to the external defibrillator. The replaceable supply module may be a container with compartments to contain the pads and battery. The container may have a peelable top surface, and may be configured such that operation of the defibrillator is initiated by peeling the peelable top surface. The replaceable supply module has an expiration date, which may be the earlier of an expiration date of the pads and an expiration date of the battery. The expiration date may take on many forms, such as visible indicia printed on an surface of the replaceable supply module, or indicia in machine-readable form readable by the defibrillator. When the expiration date is in machine readable form, the defibrillator is able to monitor the expiration date and communicate information regarding the expiration date locally or remotely.
In another aspect, the defibrillator is configured to conduct a periodic test of the replaceable supply module in connection with or separate from periodic self tests. The results of the periodic tests of the replaceable supply module are communicated locally or remotely by the defibrillator display or communication unit respectively. The defibrillator may be configured to compare the expiration date of the supply module with the current date, and to issue at least one of an audible and visual warning indicating that the supply module has passed its expiration date or is approaching its expiration date.
In another embodiment, the defibrillation system includes a defibrillator configured to monitor a supply module and a supply module containing pads and a battery electrically connectable to the defibrillator. The supply module may also contain ECG leads, gloves, a CPR barrier mask, a PCMCIA memory card, scissors and a memory. The memory is configured to store information for transmission from the supply module to the defibrillator, such as information related to the expiration date of the supply module, expiration dates of items contained by the supply module, training scenarios, codes necessary for operation of the defibrillator or software and algorithms usable by the defibrillator during the defibrillation process. Likewise, the supply module may contain a memory configured to store information received from the defibrillator, such as ECG data, event data and audio data.